The only real problem is likely if you set the downloads folder to be some folder under 'Program Files (x86)', I think it defaults to your vista/7 'Downloads' folder now, but for a while it did default to a subfolder of the installation path.

As with any program under vista/7, write access to 'Program Files'/'Program Files (x86)' is severely curtailed, even when granted administrative rights via UAC.

It's possible this would be a source of problems for people with 7 in the past, especially if they did an inplace upgrade from XP where the program files folder would be the location for downloaded torrents.